In the manufacture of TFT-LCDs (liquid crystal display devices), a photoresist is required, wherein in the manufacture of a CF (color filter) substrate, necessary RGB photoresist has a strict requirement for the homogeneity of a photoresist amount. The long-distance transportation and the long-period storage of the photoresist may result in the settlement thereof. In a photoresist tank, the amount of photoresist in an upper part is smaller than that in a lower part. Since the CF adopts the negative photoresist (i.e., a part of exposed photoresist will be retained), if the homogeneity of the photoresist is not good, after the procedures of vacuum pumping and preheating, the amounts of retained photoresist may be different due to the volatilization of a solvent in the photoresist, which results in a difference in characteristic values, thereby influencing the quality of the products.
An existing photoresist tank has no design for preventing or treating the photoresist settlement. A commonly adopted treating procedure is to roll or sway the photoresist tank. Since the photoresist tank is heavy, the operation is inconvenient. Moreover, since the photoresist is inflammable and possesses some toxicity, there also exists a safety problem in the operation.